Imaging lens assembly

ABSTRACT

A multi-element imaging lens can be formed from five plastic elements, and an optional null-power or relatively low power sixth plastic element. The lens can use selected plastic materials to reduce a thermal focal shift. In the lens, negative refractive power elements can be formed from plastic materials having a relatively large negative refractive index variation with temperature, abbreviated as dn/dT, while positive refractive power elements can be formed from plastic materials having a relatively small negative dn/dT. Reducing the thermal focal shift, as disclosed, can eliminate the need for an auto-focusing device, such as a voice coil. Reducing the thermal focal shift, as disclosed, can also eliminate the need to use one or more glass elements to further reduce thermal focal shift, which can reduce cost for the lens.

PRIORITY

This application is a continuation of U.S. application Ser. No.16/483,973, filed Aug. 6, 2019, which application claims the benefit ofpriority to U.S. Provisional Patent Application Ser. No. 62/455,983,filed Feb. 7, 2017, the benefit of priority of which are claimed hereby,and which are incorporated by reference herein in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to an imaging lens assembly.

BACKGROUND OF THE DISCLOSURE

It is difficult to design and manufacture an imaging lens assembly thatmaintains its focus over a suitable wide range of temperatures. Forexample, at particular temperatures, thermal variation of the refractiveindex of the lens elements can translate the focal plane of the imaginglens assembly toward or away from a sensor, leading to a blurry image onthe sensor.

SUMMARY

In one example of an imaging lens assembly having a positive totalrefractive power, the imaging lens assembly can include, in order froman object side to an image side: a first lens element with negativerefractive power between 51% and 68% of the total refractive power; asecond lens element with zero or positive refractive power between 0%and 5% of the total refractive power; a third lens element with positiverefractive power between 75% and 110% of the total refractive power; afourth lens element with negative refractive power between 42% and 61%of the total refractive power; a fifth lens element with positiverefractive power between 91% and 112% of the total refractive power; anda sixth lens element with a negative refractive power between 38% and97% of the total refractive power.

In another example of an imaging lens assembly having a positive totalrefractive power, the imaging lens assembly can include, in order froman object side to an image side: a first lens element with negativerefractive power and formed from a material having an Abbe numbergreater than 50; a second lens element formed from a material having anAbbe number less than 35; a third lens element with positive refractivepower and formed from a material having an Abbe number greater than 50;a fourth lens element with negative refractive power and formed from amaterial having an Abbe number less than 27; a fifth lens element withpositive refractive power and formed from a material having an Abbenumber greater than 50; and a sixth lens element with a negativerefractive power and formed from a material having an Abbe number lessthan 27.

In another example of an imaging lens assembly having a positive totalrefractive power, the imaging lens assembly can include, in order froman object side to an image side: a first lens element with negativerefractive power between 51% and 68% of the total refractive power; asecond lens element with positive refractive power between 75% and 110%of the total refractive power; a third lens element with negativerefractive power between 42% and 61% of the total refractive power; afourth lens element with positive refractive power between 91% and 112%of the total refractive power; and a fifth lens element with a negativerefractive power between 38% and 97% of the total refractive power.

In another example of an imaging lens assembly having a positive totalrefractive power, the imaging lens assembly can include, in order froman object side to an image side: a first lens element with negativerefractive power and formed from a material having an Abbe numbergreater than 50; a second lens element with positive refractive powerand formed from a material having an Abbe number greater than 50; athird lens element with negative refractive power and formed from amaterial having an Abbe number less than 27; a fourth lens element withpositive refractive power and formed from a material having an Abbenumber greater than 50; and a fifth lens element with a negativerefractive power and formed from a material having an Abbe number lessthan 27.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional side view of an imaging lens assembly, inaccordance with some examples, with examples of light rays superimposedon the lens surfaces.

FIG. 2 shows the cross-sectional side view of the imaging lens assemblyof FIG. 1 , in accordance with some examples, with the light raysremoved.

FIG. 3 includes a table showing three suitable ranges of relative powervalues for each lens element, for the imaging lens assembly of FIGS. 1and 2 , in accordance with some examples.

FIGS. 4 and 5 include tables showing a prescription of a first sampleimaging lens assembly design, in accordance with some examples.

FIGS. 6 and 7 include tables showing a prescription of a second sampleimaging lens assembly design, in accordance with some examples.

FIG. 8 shows an example of a device that includes an imaging lensassembly, in accordance with some examples.

Corresponding reference characters indicate corresponding partsthroughout the several views. Elements in the drawings are notnecessarily drawn to scale. The configurations shown in the drawings aremerely examples, and should not be construed as limiting the scope ofthe invention in any manner.

DETAILED DESCRIPTION

A multi-element imaging lens can be formed from five plastic elements,and an optional null-power or relatively low power sixth plasticelement. The lens can use selected plastic materials to reduce a thermalfocal shift. In the lens, negative refractive power elements can beformed from plastic materials having a relatively large (absolutemagnitude) negative refractive index variation with temperature,abbreviated as dn/dT, while positive refractive power elements can beformed from plastic materials having a relatively small (absolutemagnitude) negative dn/dT. Reducing the thermal focal shift, asdisclosed, can eliminate the need for an auto-focusing device, such as avoice coil. Reducing the thermal focal shift, as disclosed, can alsoeliminate the need to use one or more glass elements to further reducethermal focal shift, which can reduce cost for the lens.

In the following discussion, the Abbe number (also known as V-number) ofa material is defined as defined as the dimensionless quantity(n_(d)−1)/(n_(F)−n_(C)), where nd is a refractive index of the materialat a wavelength of 587.6 nm (helium d-line), n_(F) is a refractive indexof the material at a wavelength of 486.1 nm (hydrogen F-line), and n_(C)is a refractive index of the material at a wavelength of 656.3 nm(hydrogen C-line). In general, the higher the Abbe number of a material,the lower the dispersion of the material.

In the following discussion, the quantity dn/dT is used to represent achange in refractive index (n) of a material, with respect totemperature (T). The quantity dn/dT is evaluated at a temperature of 25C, at a wavelength of 587.6 nm (helium d-line). The higher the value ofdn/dT, the greater the variation in refractive index with temperature.In the following discussion, when a size of the quantity dn/dT ismentioned, it will be understood that the size corresponds to a size ofan absolute magnitude of the quantity dn/dT. Relatively large values ofdn/dT are farther away from zero than relatively small values of dn/dT.In addition, it will be understood that the values of Abbe number anddn/dT can vary slightly from batch-to-batch of the optical material.Although optical material manufacturers typically attempt to minimizebatch-to-batch variations, some variation is unavoidable in practice.The values of Abbe number and dn/dT discussed herein are publishedvalues specified by the material manufacturers.

The following discussion mentions various optical plastic materials, allof which are commercially available, and all of which have well-definedand well-documented optical and mechanical properties that are readilyknown to one of ordinary skill in the art. The plastic materialsdiscussed herein can be formed of one or more polymeric materials,and/or one or more plastic materials. In some examples, the plasticmaterials discussed herein exclude glass materials and/or exclude fusedsilica.

In the discussion that follows, various optical elements are referred toas first lens element, second lens element, and so forth. It will beunderstood that the numbering scheme is provided merely for convenience,and to specify an order in which the numbered elements appear. In someexamples, one or more additional optical elements can optionally appearbetween the numbered elements. For example, a planar spectral filter canappear before a first lens element, between a first lens element and asecond lens element, between a second lens element and a third lenselement, between a fifth lens element and a sixth lens element, after asixth lens element, and so forth.

FIG. 1 shows a cross-sectional side view of an imaging lens assembly 10,in accordance with some examples, with examples of simulated light rayssuperimposed on the lens surfaces. FIG. 2 shows the cross-sectional sideview of the imaging lens assembly of FIG. 1 , in accordance with someexamples, with the light rays removed.

Such an imaging lens assembly 10 is suitable for relatively wide-angleapplication, such as a mobile phone. The example of FIG. 1 is but oneexample of an imaging lens assembly 10; other suitable imaging lensassemblies can also be used.

The imaging lens assembly 10 can have a positive total refractive power.The imaging lens assembly 10 can be scaled in size as needed, toaccommodate a desired focal length or desired refractive power(typically represented as 1/the focal length). For discussion below, thepower of each lens element is scaled by the total refractive power ofthe imaging lens assembly 10.

The imaging lens assembly 10 can include, in order from an object sideto an image side, a first lens element 12, an optional second lenselement 14, a third lens element 16, a fourth lens element 18, a fifthlens element 20, and a sixth lens element 22. A blue glass absorptivefilter 24 can be positioned between the sixth lens element 22 and animage plane 26. FIG. 2 shows an aperture stop 28 of the imaging lensassembly 10 positioned at an object-side surface of the third lenselement 16.

Each lens element includes an object-facing surface and an image-facingsurface opposite the object-facing surface. The object-facing surfaceand the image-facing surface can each be shaped to have a base radius ofcurvature. The radii of curvature of the two surfaces, the refractiveindex of the element material, and a vertex-to-vertex (e.g., on-axis)thickness between the surfaces can determine an optical power of theelement, in accordance with the well-known lensmaker's equation. Foraspheric surfaces, each surface can additionally include a conicconstant, denoted as quantity k, which may or may not be zero. Foraspheric surfaces, each surface can additionally include one or moreaspheric coefficients, denoted as quantities A4, A6, A8, and so forth,each of which may or may not be zero. Spherical surfaces include a conicconstant of zero and aspheric coefficients that all equal zero.

The precise shapes of the lens element surfaces can be varied withinparticular ranges. FIG. 3 includes a table showing three suitable rangesof relative power values for each lens element, for the imaging lensassembly of FIGS. 1 and 2 , in accordance with some examples. Each valuein the table of FIG. 3 is normalized by the total power of the lensassembly.

In some examples, the first lens element 12 can have negative refractivepower between 51% and 68% of the total refractive power. In someexamples, the first lens element 12 can have negative refractive powerbetween 60% and 68% of the total refractive power. In some examples, thefirst lens element 12 can have negative refractive power between 60% and65% of the total refractive power. In some examples, the first lenselement 12 can be formed from a material having an Abbe number greaterthan 50. In some examples, the first lens element 12 can be formed froma material having a dn/dT less than −99×10⁻⁶/° C. In some examples, thefirst lens element 12 can be formed from one of Zeonex 480R, Zeonex330R, or APL5014CL. In some examples, the first lens element 12 can beformed from Zeonex 480R, which has an Abbe number of 56, and has a dn/dTof −106×10⁻⁶/° C. In some examples, the first lens element 12 can use ahigh index crown material, such as Zeonex 480R, which is unusual fortypical multi-element imaging lens designs.

In some examples, the optional second lens element 14 can have zero orpositive refractive power between 0% and 5% of the total refractivepower. In some examples, the optional second lens element 14 can havezero refractive power, such a planar element. In some examples, thesecond lens element 14 can be formed from a material having an Abbenumber less than 35. In some examples, the second lens element 14 can beformed from one of OKP-A1, OKP1, Ultem PEI (Polyetherimide),polystyrene, or polycarbonate. In some examples, the second lens element14 can be formed from OKP-A1, which has an Abbe number of 22, and has adn/dT of −133×10⁻⁶/° C. In some examples, the second lens element 14 canintroduce lateral chromatic aberration correction with little impact toathermalization, as-built performance, or cost.

In some examples, the third lens element 16 can have positive refractivepower between 75% and 110% of the total refractive power. In someexamples, the third lens element 16 can have positive refractive powerbetween 75% and 105% of the total refractive power. In some examples,the third lens element 16 can have positive refractive power between 75%and 80% of the total refractive power. In some examples, the third lenselement 16 can be formed from a material having an Abbe number greaterthan 50. In some examples, the third lens element 16 can be formed froma material having a material having a dn/dT greater than −95×10⁻⁶/° C.In some examples, the third lens element 16 can be formed from ZeonexF52R, which has an Abbe number of 56, and has a dn/dT of −93×10⁻⁶/° C.In some examples, an aperture stop 28 of the imaging lens assembly 10can be positioned at an object-side surface of the third lens element16.

In some examples, the fourth lens element 18 can have negativerefractive power between 42% and 61% of the total refractive power. Insome examples, the fourth lens element 18 can have negative refractivepower between 42% and 58% of the total refractive power. In someexamples, the fourth lens element 18 can be formed from a materialhaving an Abbe number less than 27. In some examples, the fourth lenselement 18 can be formed from a material having a dn/dT less than−118×10⁻⁶/° C. In some examples, the fourth lens element 18 can beformed from one of OKP4, OKP1, OKP-A1, OKP-A2, or EP-8000. In someexamples, the fourth lens element 18 can be formed from OKP4, which hasan Abbe number of 27, and has a dn/dT of −152×10⁻⁶/° C.

In some examples, the fifth lens element 20 can have positive refractivepower between 91% and 112% of the total refractive power. In someexamples, the fifth lens element 20 can have positive refractive powerbetween 91% and 101% of the total refractive power. In some examples,the fifth lens element 20 can have positive refractive power between 99%and 100% of the total refractive power. In some examples, the fifth lenselement 20 can be formed from a material having an Abbe number greaterthan 50. In some examples, the fifth lens element 20 can be formed froma material having a dn/dT greater than −95×10⁻⁶/° C. In some examples,the fifth lens element 20 can be formed from Zeonex F52R, which has anAbbe number of 56, and has a dn/dT of −93×10⁻⁶/° C.

In some examples, the sixth lens element 22 can have negative refractivepower between 38% and 97% of the total refractive power. In someexamples, the sixth lens element 22 can have negative refractive powerbetween 38% and 61% of the total refractive power. In some examples, thesixth lens element 22 can have negative refractive power between 38% and44% of the total refractive power. In some examples, the sixth lenselement 22 can be formed from a material having an Abbe number less than27. In some examples, the sixth lens element 22 can be formed from amaterial having a dn/dT less than −118×10⁻⁶/° C. In some examples, thesixth lens element 22 can formed from one of OKP1, OKP4, OKP-A1, OKP-A2,EP-8000, or Ultem PEI. In some examples, the sixth lens element 22 canbe formed from OKP1, which has an Abbe number of 22, and has a dn/dT of−138×10⁻⁶/° C. In some examples, the fourth lens element 18 and thesixth lens element 22 can be low Abbe number flints, such as PEI orEP-8000. The large magnitude negative dn/dT materials in the OKP catalogfor the fourth and sixth lens elements can compromise lateral chromaticaberration correction and, as a result, are not used in typicalmulti-element imaging lenses. Using the large magnitude negative dn/dTmaterials in the present design therefore provides an unexpected benefitfor athermalization.

In some examples, the designs can use all plastic elements in a plasticbarrel with plastic spacers. Although plastic elements tend to haverelatively large coefficients of thermal expansion, the design canreduce or minimize the thermal focal shift, by selecting materials witha relatively large negative dn/dT for the negative-powered lens elementsand a relatively small negative dn/dT for the positive-powered lenselements. In some examples, the plastic optics can have coefficients ofthermal expansion between 59×10⁻⁶/° C. and 74×10⁻⁶/° C. In practice, theperformance of the lens can be relatively insensitive to thermalexpansion of the plastic optics, for values in the cited range. In someexamples, the spacers, holder, and lens barrel can all have coefficientsof thermal expansion of 55×10⁻⁶/° C. In practice, values greater thanthe cited value can improve athermalization of the lens, and can also beused.

FIGS. 4 and 5 include tables showing a prescription of a first sampleimaging lens assembly design (“Design 1”), in accordance with someexamples. Design 1 omits the optional second element. The prescriptionof Design 1 is consistent with the ranges shown in FIG. 3 .

FIGS. 6 and 7 include tables showing a prescription of a second sampleimaging lens assembly design (“Design 2”), in accordance with someexamples. Design 2 includes the optional second element. Theprescription of Design 2 is consistent with the ranges shown in FIG. 3 .

To evaluate the configuration of Design 2 (FIGS. 6 and 7 ), the imaginglens assembly 10 is scaled to have an effective focal length of 1.57 mm,or, equivalently, a total refractive power of 0.637 mm⁻¹. After scaling,the imaging lens assembly 10 has a length of 6.71 mm, from theobject-side surface of the first lens element 12 to the image plane 26.The field of view is set to 115 degrees at a diagonal, with 120 degreesto an image circle. At this field of view, the f-number of the imaginglens assembly 10 is 2.4. At an image height of 1.98 mm, the calculateddistortion is −20.4%. The following paragraphs summarize a simulatedperformance of the lens of Design 2.

At a temperature of 20 C, a polychromatic (e.g., using wavelengths from486.1 nm to 656.3 nm) Modulation Transfer Function (MTF), at 76 cyclesper mm, has a value of 0.80 for a sagittal image height of 0 mm, a valueof 0.80 for a sagittal image height of 0.792 mm, a value of 0.75 for asagittal image height of 1.188 mm, a value of 0.72 for a sagittal imageheight of 1.584 mm, a value of 0.80 for a tangential image height of 0mm, a value of 0.79 for a tangential image height of 0.792 mm, a valueof 0.66 for a tangential image height of 1.188 mm, and a value of 0.70for a tangential image height of 1.584 mm.

At a temperature of 40 C, a polychromatic MTF, at 76 cycles per mm, hasa value of 0.84 for a sagittal image height of 0 mm, a value of 0.84 fora sagittal image height of 0.792 mm, a value of 0.78 for a sagittalimage height of 1.188 mm, a value of 0.70 for a sagittal image height of1.584 mm, a value of 0.84 for a tangential image height of 0 mm, a valueof 0.84 for a tangential image height of 0.792 mm, a value of 0.67 for atangential image height of 1.188 mm, and a value of 0.66 for atangential image height of 1.584 mm.

At a temperature of 60 C, a polychromatic MTF, at 76 cycles per mm, hasa value of 0.80 for a sagittal image height of 0 mm, a value of 0.80 fora sagittal image height of 0.792 mm, a value of 0.75 for a sagittalimage height of 1.188 mm, a value of 0.65 for a sagittal image height of1.584 mm, a value of 0.80 for a tangential image height of 0 mm, a valueof 0.69 for a tangential image height of 0.792 mm, a value of 0.60 for atangential image height of 1.188 mm, and a value of 0.56 for atangential image height of 1.584 mm.

At a temperature of 20 C, the on-axis (e.g., sagittal image height of 0mm and tangential image height of 0 mm) polychromatic MTF peaks at avalue of 0.84 at a focus shift of about −5 microns, and falls to 0.42 atfocus shifts of −30 microns and +20 microns.

At a temperature of 40 C, the on-axis polychromatic MTF peaks at a valueof 0.84 at a focus shift of about +2 microns, and falls to 0.42 at focusshifts of −23 microns and +27 microns.

At a temperature of 60 C, the on-axis polychromatic MTF peaks at a valueof 0.84 at a focus shift of about +7 microns, and falls to 0.42 at focusshifts of −18 microns and +34 microns.

A lateral color at a wavelength of 410 nm rises from 0 microns to amaximum value of about 8.0 microns, then falls to about 1.8 microns at amaximum field of 57.5 degrees. A lateral color at a wavelength of 486.1nm rises from 0 microns to a maximum value of about 1.1 microns, thenfalls to about −1.8 microns at a maximum field of 57.5 degrees. Alateral color at a wavelength of 587.6 nm is set to the reference level(e.g., remains 0 microns over the full field). A lateral color at awavelength of 656.3 nm rises from 0 microns to a maximum value of about1.5 microns at a maximum field of 57.5 degrees. For reference, the Airydisc radius is about +/−2 microns at the reference wavelength of 587.6nm.

An incident angle for a chief ray rises from 0 degrees at an imageheight of 0 mm to +30 degrees at an image height of 1.98 mm. An incidentangle for a lower rim ray rises from −12 degrees at an image height of 0mm to +22 degrees at an image height of 1.98 mm. An incident angle foran upper rim ray rises from +12 degrees at an image height of 0 mm to+40 degrees at an image height of 1.98 mm.

A field curvature at a wavelength of 486 nm drops from 0 microns on-axisto about −54 microns at a field of 57.5 degrees in the sagittaldirection, and oscillates between about −10 microns and +10 microns overthe field in the tangential direction. A field curvature at a wavelengthof 588 nm drops from −14 microns on-axis to about −62 microns at a fieldof 57.5 degrees in the sagittal direction, and oscillates between about−14 microns and +31 microns over the field in the tangential direction.A field curvature at a wavelength of 656 nm drops from −17 micronson-axis to about −63 microns at a field of 57.5 degrees in the sagittaldirection, and oscillates between about −17 microns and +41 microns overthe field in the tangential direction.

An f-tan distortion rises from 0% on-axis to about −20% at a field of57.5 degrees.

A relative illumination drops from 1.0 on-axis, to about 0.58 at a fieldof 57.5 degrees.

In the design phase, the lens prescriptions can be altered slightly, toaccommodate a continuum of lens designs that can range from excellentathermalization with poor as-built performance to poorer athermalizationwith excellent as-built performance.

For a configuration in which the performance is best athermalized, thematerials of the first through sixth lens elements can be Zeonex 480R,OKP1, Zeonex F52R, OKP4, Zeonex F52R, and OKP4, respectively. For thesematerials, the full thermal shift from 25 C to 60 C is 6.5 microns.

For a configuration in which the performance is best compromised, thematerials of the first through sixth lens elements can be Zeonex 480R,OKP-A1, Zeonex F52R, OKP4, Zeonex F52R, and OKP-A1, respectively. Forthese materials, the full thermal shift from 25 C to 60 C is 8 microns.

For a configuration in which the performance is highest yielding, thematerials of the first through sixth lens elements can be Zeonex 480R,OKP-A1, Zeonex F52R, OKP1, Zeonex F52R, and OKP4, respectively. Forthese materials, the full thermal shift from 25 C to 60 C is 11 microns.

For a configuration in which the performance is best compromised inwhich the optional second element is eliminated, the materials of thefirst and third through fifth lens elements can be Zeonex 480R, ZeonexF52R, OKP4, Zeonex F52R, and OKP-A1 or OKP1, respectively. For thesematerials, the full thermal shift from 25 C to 60 C is 9 microns.

For a configuration in which the second element is powered, thematerials of the first through sixth lens elements can be Zeonex 480R,PEI, Zeonex F52R, OKP4, Zeonex F52R, and OKP4, respectively.

For a configuration that can use a reduced-size sensor, the materials ofthe first through sixth lens elements can be Zeonex 480R, Polystyrene,Zeonex F52R, OKP4, Zeonex F52R, and OKP4, respectively.

For comparison, a typical plastic design with these parameters can havea full thermal shift of 22 to 26 microns, a typical plastic design witha glass molded optic can have a thermal shift of 16 microns, and awell-corrected plastic design with a glass molded optic can have athermal shift of 4 microns.

FIG. 8 shows an example of a device 800 that includes an imaging lensassembly, such as assembly 10 of FIGS. 1 and 2 , in accordance with someexamples. The device 800 can be a mobile phone with a camera, astand-alone camera, a camera integrated with an additional piece ofequipment, or another suitable device. The device 800 can include ahousing 812 that surrounds the components of the device 800. The device800 can include the optical elements of the lens assembly 10 mounted ina plastic barrel with plastic spacers 802. Light from an object passesthrough the lens assembly 10. A sensor 26 can detect the light from thelens assembly 10. The sensor 26 can convert the sensed light to anelectrical signal. Circuitry 806 can convert the electrical signal intodata representing an image at the sensor 26. The circuitry 806 caninclude a processor 808. The circuitry can include memory 810. Thememory 810 can include instructions that, when executed by the processor808, cause the processor to execute instructions. The instructions caninclude processing the electrical signal, storing and accessing storedimages, and the like.

While this invention has been described as having example designs, thepresent invention can be further modified within the spirit and scope ofthis disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains and which fallwithin the limits of the appended claims.

To further illustrate the device disclosed herein, a non-limiting listof examples is provided below. Each of the following non-limitingexamples can stand on its own, or can be combined in any permutation orcombination with any one or more of the other examples.

Example 1: An imaging lens assembly having a positive total refractivepower, the imaging lens assembly comprising in order from an object sideto an image side: a first lens element with negative refractive powerbetween 51% and 68% of the total refractive power; a second lens elementwith zero or positive refractive power between 0% and 5% of the totalrefractive power; a third lens element with positive refractive powerbetween 75% and 110% of the total refractive power; a fourth lenselement with negative refractive power between 42% and 61% of the totalrefractive power; a fifth lens element with positive refractive powerbetween 91% and 112% of the total refractive power; and a sixth lenselement with a negative refractive power between 38% and 97% of thetotal refractive power.

Example 2: The imaging lens assembly of example 1, wherein the first,second, third, fourth, fifth, and sixth elements are formed fromplastic.

Example 3: The imaging lens assembly of any one of examples 1-2, whereinthe first, second, third, fourth, fifth, and sixth elements are mountedin a plastic barrel and are spaced apart by plastic spacers.

Example 4: The imaging lens assembly of any one of examples 1-3,wherein: the first lens element is formed from a material having an Abbenumber greater than 50; the second lens element is formed from amaterial having an Abbe number less than 35; the third lens element isformed from a material having an Abbe number greater than 50; the fourthlens element is formed from a material having an Abbe number less than27; the fifth lens element is formed from a material having an Abbenumber greater than 50; and the sixth lens element is formed from amaterial having an Abbe number less than 27.

Example 5: The imaging lens assembly of any one of examples 1-4,wherein: the first lens element is formed from a material having a dn/dTless than −99×10⁻⁶/° C.; the third lens element is formed from amaterial having a dn/dT greater than −95×10⁻⁶/° C.; the fourth lenselement is formed from a material having a dn/dT less than −118×10⁻⁶/°C.; the fifth lens element is formed from a material having a dn/dTgreater than −95×10⁻⁶/° C.; and the sixth lens element is formed from amaterial having a dn/dT less than −118×10⁻⁶/° C.

Example 6: The imaging lens assembly of any one of examples 1-5,wherein: the first lens element is formed from Zeonex 480R, has an Abbenumber of 56, and has a dn/dT of −106×10⁻⁶/° C.; the second lens elementis formed from OKP-A1, has an Abbe number of 22, and has a dn/dT of−133×10⁻⁶/° C.; the third lens element is formed from Zeonex F52R, hasan Abbe number of 56, and has a dn/dT of −93×10⁻⁶/° C.; the fourth lenselement is formed from OKP4, has an Abbe number of 27, and has a dn/dTof −152×10⁻⁶/° C.; the fifth lens element is formed from Zeonex F52R,has an Abbe number of 56, and has a dn/dT of −93×10⁻⁶/° C.; and thesixth lens element is formed from OKP1, has an Abbe number of 22, andhas a dn/dT of −138×10⁻⁶/° C.

Example 7: The imaging lens assembly of any one of examples 1-6, whereinthe first, third, fourth, fifth, and sixth lens elements are aspheric.

Example 8: The imaging lens assembly of any one of examples 1-7, whereinan aperture stop of the imaging lens assembly is positioned at anobject-side surface of the third lens element.

Example 9: The imaging lens assembly of any one of examples 1-8, furthercomprising a blue glass absorptive filter positioned between the sixthlens element and an image plane.

Example 10: An imaging lens assembly having a positive total refractivepower, the imaging lens assembly comprising in order from an object sideto an image side: a first lens element with negative refractive powerand formed from a material having an Abbe number greater than 50; asecond lens element formed from a material having an Abbe number lessthan 35; a third lens element with positive refractive power and formedfrom a material having an Abbe number greater than 50; a fourth lenselement with negative refractive power and formed from a material havingan Abbe number less than 27; a fifth lens element with positiverefractive power and formed from a material having an Abbe numbergreater than 50; and a sixth lens element with a negative refractivepower and formed from a material having an Abbe number less than 27.

Example 11: The imaging lens assembly of example 10, wherein the first,second, third, fourth, fifth, and sixth elements are formed fromplastic.

Example 12: The imaging lens assembly of any one of examples 10-11,wherein the first, second, third, fourth, fifth, and sixth elements aremounted in a plastic barrel and are spaced apart by plastic spacers.

Example 13: The imaging lens assembly of any one of examples 10-12,wherein: the first lens element has a negative refractive power between51% and 68% of the total refractive power; the second lens element has azero or positive refractive power between 0% and 5% of the totalrefractive power the third lens element has a positive refractive powerbetween 75% and 110% of the total refractive power; the fourth lenselement has a negative refractive power between 42% and 61% of the totalrefractive power; the fifth lens element has a positive refractive powerbetween 91% and 112% of the total refractive power; and the sixth lenselement has a negative refractive power between 38% and 97% of the totalrefractive power.

Example 14: The imaging lens assembly of any one of examples 10-13,wherein the first, third, fourth, fifth, and sixth lens elements areaspheric.

Example 15: The imaging lens assembly of any one of examples 10-14,wherein an aperture stop of the imaging lens assembly is positioned atan object-side surface of the third lens element.

Example 16: The imaging lens assembly of any one of examples 10-15,wherein: the first lens element is formed from a material having a dn/dTless than −99×10⁻⁶/° C.; the third lens element is formed from amaterial having a dn/dT greater than −95×10⁻⁶/° C.; the fourth lenselement is formed from a material having a dn/dT less than −118×10⁻⁶/°C.; the fifth lens element is formed from a material having a dn/dTgreater than −95×10⁻⁶/° C.; and the sixth lens element is formed from amaterial having a dn/dT less than −118×10⁻⁶/° C.

Example 17: The imaging lens assembly of any one of examples 10-16,wherein: the first lens element is formed from Zeonex 480R, has an Abbenumber of 56, and has a dn/dT of −106×10⁻⁶/° C.; the second lens elementis formed from OKP-A1, has an Abbe number of 22, and has a dn/dT of−133×10⁻⁶/° C.; the third lens element is formed from Zeonex F52R, hasan Abbe number of 56, and has a dn/dT of −93×10⁻⁶/° C.; the fourth lenselement is formed from OKP4, has an Abbe number of 27, and has a dn/dTof −152×10⁻⁶/° C.; the fifth lens element is formed from Zeonex F52R,has an Abbe number of 56, and has a dn/dT of −93×10⁻⁶/° C.; and thesixth lens element is formed from OKP1, has an Abbe number of 22, andhas a dn/dT of −138×10⁻⁶/° C.

Example 18: The imaging lens assembly of any one of examples 10-17,further comprising a blue glass absorptive filter positioned between thesixth lens element and an image plane.

Example 19: An imaging lens assembly having a positive total refractivepower, the imaging lens assembly comprising in order from an object sideto an image side: a first lens element with negative refractive powerbetween 51% and 68% of the total refractive power; a second lens elementwith positive refractive power between 75% and 110% of the totalrefractive power; a third lens element with negative refractive powerbetween 42% and 61% of the total refractive power; a fourth lens elementwith positive refractive power between 91% and 112% of the totalrefractive power; and a fifth lens element with a negative refractivepower between 38% and 97% of the total refractive power.

Example 20: The imaging lens assembly of example 19, wherein the first,second, third, fourth, and fifth elements are formed from plastic.

Example 21: The imaging lens assembly of any one of examples 19-20,wherein the first, second, third, fourth, and fifth elements are mountedin a plastic barrel and are spaced apart by plastic spacers.

Example 22: The imaging lens assembly of any one of examples 19-21,wherein: the first lens element is formed from a material having an Abbenumber greater than 50; the second lens element is formed from amaterial having an Abbe number greater than 50; the third lens elementis formed from a material having an Abbe number less than 27; the fourthlens element is formed from a material having an Abbe number greaterthan 50; and the fifth lens element is formed from a material having anAbbe number less than 27.

Example 23: The imaging lens assembly of any one of examples 19-22,wherein: the first lens element is formed from a material having a dn/dTless than −99×10⁻⁶/° C.; the second lens element is formed from amaterial having a dn/dT greater than −95×10⁻⁶/° C.; the third lenselement is formed from a material having a dn/dT less than −118×10⁻⁶/°C.; the fourth lens element is formed from a material having a dn/dTgreater than −95×10⁻⁶/° C.; and the fifth lens element is formed from amaterial having a dn/dT less than −118×10⁻⁶/° C.

Example 24: The imaging lens assembly of any one of examples 19-23,wherein: the first lens element is formed from Zeonex 480R, has an Abbenumber of 56, and has a dn/dT of −106×10⁻⁶/° C.; the second lens elementis formed from Zeonex F52R, has an Abbe number of 56, and has a dn/dT of−93×10⁻⁶/° C.; the third lens element is formed from OKP4, has an Abbenumber of 27, and has a dn/dT of −152×10⁻⁶/° C.; the fourth lens elementis formed from Zeonex F52R, has an Abbe number of 56, and has a dn/dT of−93×10⁻⁶/° C.; and the fifth lens element is formed from OKP1, has anAbbe number of 22, and has a dn/dT of −138×10⁻⁶/° C.

Example 25: The imaging lens assembly of any one of examples 19-24,wherein the first, second, third, fourth, and fifth lens elements areaspheric.

Example 26: The imaging lens assembly of any one of examples 19-25,wherein an aperture stop of the imaging lens assembly is positioned atan object-side surface of the second lens element.

Example 27: The imaging lens assembly of any one of examples 19-26,further comprising a blue glass absorptive filter positioned between thefifth lens element and an image plane.

Example 28: An imaging lens assembly having a positive total refractivepower, the imaging lens assembly comprising in order from an object sideto an image side: a first lens element with negative refractive powerand formed from a material having an Abbe number greater than 50; asecond lens element with positive refractive power and formed from amaterial having an Abbe number greater than 50; a third lens elementwith negative refractive power and formed from a material having an Abbenumber less than 27; a fourth lens element with positive refractivepower and formed from a material having an Abbe number greater than 50;and a fifth lens element with a negative refractive power and formedfrom a material having an Abbe number less than 27.

Example 29: The imaging lens assembly of example 28, wherein the first,second, third, fourth, and fifth elements are formed from plastic.

Example 30: The imaging lens assembly of any one of examples 28-29,wherein the first, second, third, fourth, and fifth elements are mountedin a plastic barrel and are spaced apart by plastic spacers.

Example 31: The imaging lens assembly of any one of examples 28-30,wherein: the first lens element has a negative refractive power between54% and 61% of the total refractive power; the second lens element has apositive refractive power between 99% and 105% of the total refractivepower; the third lens element has a negative refractive power between55% and 68% of the total refractive power; the fourth lens element has apositive refractive power between 81% and 91% of the total refractivepower; and the fifth lens element has a negative refractive powerbetween 61% and 68% of the total refractive power.

Example 32: The imaging lens assembly of any one of examples 28-31,wherein the first, third, fourth, and fifth lens elements are aspheric.

Example 33: The imaging lens assembly of any one of examples 28-32,wherein an aperture stop of the imaging lens assembly is positioned atan object-side surface of the second lens element.

Example 34: The imaging lens assembly of any one of examples 28-33,wherein: the first lens element is formed from a material having a dn/dTless than −99×10⁻⁶/° C.; the second lens element is formed from amaterial having a dn/dT greater than −95×10⁻⁶/° C.; the third lenselement is formed from a material having a dn/dT less than −118×10⁻⁶/°C.; the fourth lens element is formed from a material having a dn/dTgreater than −95×10⁻⁶/° C.; and the fifth lens element is formed from amaterial having a dn/dT less than −118×10⁻⁶/° C.

Example 35: The imaging lens assembly of any one of examples 28-34,wherein: the first lens element is formed from Zeonex 480R, has an Abbenumber of 56, and has a dn/dT of −106×10⁻⁶/° C.; the second lens elementis formed from Zeonex F52R, has an Abbe number of 56, and has a dn/dT of−93×10⁻⁶/° C.; the third lens element is formed from OKP4, has an Abbenumber of 27, and has a dn/dT of −152×10⁻⁶/° C.; the fourth lens elementis formed from Zeonex F52R, has an Abbe number of 56, and has a dn/dT of−93×10⁻⁶/° C.; and the fifth lens element is formed from OKP-A1, has anAbbe number of 22, and has a dn/dT of −138×10⁻⁶/° C.

Example 36: The imaging lens assembly of any one of examples 28-35,further comprising a blue glass absorptive filter positioned between thesixth lens element and an image plane.

Example 37: A mobile device, comprising a processor and memory, thememory including instructions that, when executed by the processor,cause the processor to store a digital image generated by the imaginglens assembly of any one of examples 1-36.

What is claimed is:
 1. An imaging lens assembly having a positive total refractive power, the imaging lens assembly comprising in order from an object side to an image side: a first lens element being formed from a material having a dn/dT less than −99×10⁻⁶/° C.; a second lens element with zero or positive refractive power between 0% and 5% of the total refractive power; a third lens element being formed from a material having a dn/dT greater than −95×10⁻⁶/° C.; a fourth lens element being formed from a material having a dn/dT less than −118×10⁻⁶/° C.; a fifth lens element being formed from a material having a dn/dT greater than −95×10⁻⁶/° C.; and a sixth lens element being formed from a material having a dn/dT less than −118×10⁻⁶/° C.
 2. The imaging lens assembly of claim 1, wherein the first, second, third, fourth, fifth, and sixth elements are formed from plastic.
 3. The imaging lens assembly of claim 1, wherein the first, second, third, fourth, fifth, and sixth elements are mounted in a plastic barrel and are spaced apart by plastic spacers.
 4. The imaging lens assembly of claim 1, wherein: the first lens element is formed from a material having an Abbe number greater than 50; the second lens element is formed from a material having an Abbe number less than 35; the third lens element is formed from a material having an Abbe number greater than 50; the fourth lens element is formed from a material having an Abbe number less than 27; the fifth lens element is formed from a material having an Abbe number greater than 50; and the sixth lens element is formed from a material having an Abbe number less than
 27. 5. A mobile device, comprising a processor and memory, the memory including instructions that, when executed by the processor, cause the processor to store a digital image generated by the imaging lens assembly of claim
 1. 6. The imaging lens assembly of claim 1, further comprising a blue glass absorptive filter positioned between the sixth lens element and an image plane.
 7. A method of manufacturing an imaging lens assembly, the method comprising: combining a plurality of lens elements into an imaging lens assembly, the plurality of lens elements comprising: a first lens element being formed from a material having a dn/dT less than −99×10⁻⁶/° C.; a second lens element with zero or positive refractive power between 0% and 5% of a total refractive power; a third lens element being formed from a material having a dn/dT greater than −95×10⁻⁶/° C.; a fourth lens element being formed from a material having a dn/dT less than −118×10⁻⁶/° C.; a fifth lens element being formed from a material having a dn/dT greater than −95×10⁻⁶/° C.; and a sixth lens element being formed from a material having a dn/dT less than −118×10⁻⁶/° C.
 8. The method of claim 7, wherein the first, second, third, fourth, fifth, and sixth elements are formed from plastic.
 9. The method of claim 7, wherein the first, second, third, fourth, fifth, and sixth elements are mounted in a plastic barrel and are spaced apart by plastic spacers.
 10. The method of claim 7, wherein: the first lens element is formed from a material having an Abbe number greater than 50; the second lens element is formed from a material having an Abbe number less than 35; the third lens element is formed from a material having an Abbe number greater than 50; the fourth lens element is formed from a material having an Abbe number less than 27; the fifth lens element is formed from a material having an Abbe number greater than 50; and the sixth lens element is formed from a material having an Abbe number less than
 27. 11. The method of claim 7, further comprising placing a blue glass absorptive filter between the sixth lens element and an image plane. 